Apparatus for producing concrete stair steps



Jan. 20, 1959 A. A. HART APPARATUS FOR PRODUCING CONCRETE STAIR STEPS Filed May 21, 1954 3 Sheets-Sheet 1 A. A. HART Jan. 20, 1959 APPARATUS FOR PRODUCING CONCRETE STAIR STEPS Filed May 21, 1954 3 Sheets-Sheet 2 T m e w 4 1 H 4 N UR m H a 4 .9. w R P & 3 m 1% g C ww 0T CA CH 1-||WNI\HI.M ma) Q Jan. 20, 1959 A. A. HART I 2,869,212

APPARATUS FOR PRODUCING CONCRETE STAIR STEPS Filed May 21, 1954 I a Sheets-Sheet s INVENTOR.

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nited States APPARATUS FOR PRODUCING CONCRETE STAIR STEPS This invention relates to improvements in apparatus for casting concrete stair steps.

It is the primary object of this invention to provide more eflicient and economical apparatus of this kind which is adjustable for producing concrete stair steps of differing dimensions to suit different building structures, so that sets of concrete stair steps components of appropriate dimensions can be factory produced and shipped to building sites at less cost and expenditure 'of time than such stair steps can be made at the building sites.

Another object of this invention is to provide apparatus of the character indicated above which enables stacking of sets of concrete stair steps of different anticipated dimensions ready for shipment and installation at building sites.

Still another object is to provide apparatus of the character indicated above, in which the height of the step risers can be selectively determined, while tread length thereof need be limited only by the number of such apparatus joined in end to end relation.

It is a further object of this invention to provide apparatus of the character indicated above which produces stair step components of neat appearance, desirable minimum weight and bulk for economical transportation and storage, and capable of easy and rapid assembly on building sites with a minimum of skilled labor.

A still further object of this invention is to provide apparatus of the character indicated above which is equal in appearance and structural strength to those more laboriously erected at a building site.

Other objects and advantages will become apparent from the consideration of the following detailed description, forming the specification, and taken in conjunction with the accompanying drawings, in which:

Figure 1 is a contracted top plan view, broken away intermediate its ends to show an indeterminate length, of apparatus embodying this invention for producing tread and riser units of sets of concrete stair steps;

Figure 2 is a contracted front elevational view, with parts broken away to show interior construction, taken from the right of Figure 1;

Figure 3 is an end elevational view looking from the left of Figure 2;

Figure 4 is a vertical transverse cross sectional view on line 4-4 of Figure 2;

Figure 5 is a fragmentary vertical longitudinal cross sectional view taken on line 5-5 of Figurel;

Figure 6 is a fragmentary transverse vertical section taken on line 6-6 of Figure 2 and looking in the direction of the arrows.

In order to produce a set of stair steps at a factory in accordance with dimensions for shipment to a building site, or for stockpiling, the apparatus of this invention includes a tread and riser unit producing apparatus, generally designated 10, and comprises a longitudinally elongated flat rectangular horizontal base plate 14, preferably of sheet metal, and having on its rear edge an upstanding longitudinal flange 16, preferably formed integrally thereatent O M 2,389,212 Patented Jan. 20, 1959 with and extending perpendicularly thereto, and a depending front flange 18, also preferably formed integrally with the base plate 14, and extending perpendicularly thereto along its front edge.

Similar vertical end plates 20 and 22 are secured to and depend from the base plate at opposite ends of the base plate 14. Each end plate is provided on its longitudinally outward side with a horizontal right angular flange 24 and a vertical right angular flange 26, the flange 24 extending along the upper edge of the end plate while the flange 26 extends along the front edge of the end plate. The flanges 24 bear against the underside of the base plate 14 while the vertical flanges 26 bear against the rear side of the front flange 18 of the base plate, and are secured in place by bolts 28 and 30, respectively.

Each of the end plates 20 and 22 has secured to its longitudinally outward side at its lower end a bracket plate 32 whose lower edge rests upon a lateral flange 34 on the lower edge of each end plate in spaced parallel relation to the upper flange 24. The bracket plates 32 are fixedly secured to the related end plates by rivets 36. It will be noted that the lower ends 25 of the flanges 26 of the end plates, and the lower edge 27 of the flange 18 termi nate at the upper edge 29 of the bracket plates 32.

The bracket plates 32 project forwardly beyond the base plate front flange 18 and are thereat provided with downwardly enlarged heads 38.

Secured to the longitudinally inward sides of the heads 38 by rivets 40 and 42, are rear and front guide blocks 44 and 46. The guide blocks 44 and 46 are in forwardly and rearwardly spaced relation to each other, and, as shown in Figure 5, have portions and 47 laterally spaced from this side of the heads 38, so as to provide vertical slide channels or slideways for vertical rack bars 48. The rack bars 48 have rack teeth 50 along their front edges.

A horizontal shaft 52 extends between the heads 38 and is journaled at its ends in aligned apertures 54 in the heads 38. The shaft 52 has keyed thereon pinions 55 and 56 which mesh with the teeth 50 on the rack bars 48, and bear against the longitudinally inward sides of the heads 38.

The shaft 52 is further supported at a point intermediate its ends between upper and lower clamp blocks 58 and 60 which are carried on the outwardly extending leg 62 of an L-shaped bracket 64, which is dependingly carried by and secured to a structural reinforcing channel 66 secured to the back of and extending longitudinally along the lower edge of the depending base plate front flange 18. The clamp blocks 58 and 60 are secured upon the forwardly extending leg 62 of the bracket 64 by bolts 68 and 69 the blocks 58 and 60 having arcuate seats 63 and receiving the shaft 52, as clearly shown in Figure 4.

The hub 70 of a handle 72 is pivotally mounted on the front clamp block bolt 69, and the hub 76 has a lower inclined or angular face 74 which bears upon a similar angular face 76 on the upper surface of the lower clamp back 58.

A hand wheel 78 is keyed on the shaft 52 at a location between the bracket 64 and the pinion 56.

The heads 38 are provided in their upper edges with slots 80, the slots 80 being in longitudinal alignment and receiving the lower longitudinal edge 32 of a vertical longitudinally elongated removable front panel 48. The front panel 48 is a plate of sheet metal and extends in forwardly spaced parallel relation to the depending base plate flange 18.

Secured to the front side of the panel 84 is an upper horizontal reinforcing channel bar 88 located at the upper edge of the panel, and a lower reinforcing channel 3 bar 86 spaced below the bar 88 and spaced above the lower edge 82 of the panel 84.

The rack bars 48 have on their upper ends laterally inwardly extending flanges 90 upon which are secured the opposite ends of the web 93 of an inverted horizontal channel 94. The channel 94 is positioned between the front side of the base plate front flange 18 and the'i'ear side of the panel 84 and has depending rear and front flanges 97 and 99, respectively, bearing slidably th'er'eagainst.

A horizontal reinforcing channel bar 96 is secured along the rear side of the rear base plate flange 16 at its upper edge. A pair of clamping brackets, generally designated 98 and 100 respectively, are carried in spaced relation on the channel bar 96 which serves as a track for the clamp brackets so that they can be moved along the channel 96. The clamping brackets 98 and 100 are identical, and each comprises a clamping screw 102 carried by the rear depending le'g 104 of a bracket yoke 106 which is in sliding and overlying embracing relation to the track channel bar 96. Also, each of the clamping brackets has an arm 108, pivotally mounted thereon at 112 at its rear end on the longitudinally inward side of a group of transversely elongated plates 109, 110 and 111, which are in side by side relation. The pivot 112 is at a location intermediate the ends of the plates with the arm 108 extending forwardly beyond the longitudinally inward plate 109. The arm 108 carries on its forward end a detent 114 to be engaged over the upper reinforcing channel bar 88 on the frontpanel 48.

The forward end of the middle plate 110 has thereon an extension 115 which extends beyond the forward ends of the other plates 109 and 111 and is secured between the longitudinally inwardly and outwardly spaced, vertically elongated plates 116 and 118 above a shorter middle vertical plate 120 of a group of vertical elongated plates. The plates 116, 118 and 120 are positioned between the front side of the base plate front flange 1S and the rear side of the panel 48 and have their lower edges resting upon the web 93 of the channel 94, so that the groups composed of the plates 116, 118 and 120 are held in vertical positions and are guided in vertical movement by the extensions 115 of the middle plates 110. Thus there is sliding operative engagement between the plates of the clamping brackets and the plates 116, 118 and 120, which serve as spacers and guides for the panel 48, and as mold end plates.

Each of the clamping brackets 98 and 100 has a generally triangular horizontal reinforcing web 122 on the bracket yoke 106 which extends along the longitudinally outward side of the plates 109, 110 and 111, and has on its forward end a depending arm 124 adapted to contact the forward side of the base plate flange 18 to serve as a guide and reinforcing member for the plates 116, 118 and 120.

To use the apparatus or machine 10, the clamping brackets 98 and 100, which are free to slide along the channel 96 longitudinally thereof, when the screws 102 are released from locking engagement with the track channel bar 96. The front panel 84 is removed from the machine or apparatus 10, and the handle 72 turned to a position wherein the clamp blocks 53 and 60 are released from the shaft 52 used permit rotation thereof. The machine 10 may be attached to a bench or other suitable support by suitable fastening devices passing through openings, such as the opening 126, in the outwardly extending leg 128 of the respective bracket plates 32 carried on the end plates 20 and 22 (see Figure Since the height of a combined tread and riser unit, and the width of its tread vary with different specifications and requirements, it is necessary to set the machine to produce a tread and riser of the prescribed dimensions. In order to do this, the hand wheel 78 is rotated to cause rotation of the pinions 55 and 56, and consequent vertical movement of the related rack bars 48, and thereby cause vertical movement of the channel 94. By measuring from the surface of the web 93 of the channel 94 to the top surface of the base plate 14, the riser height will be set. When the proper riser height is attained, the handle 72 is rotated so that its angular face is moved into camming engagement with the mating angular face on the lower clamp block 58 so that the clamp block 58 is moved toward the complemental clamp block 60 to serve as a brake on the shaft 52 and thus prevent further rotaticn thereof. This locks the channel 94 at the selected elevation.

The clamping brackets 98 and are then moved along the track 96 toward or away from each other to a preetermined distance apart, and specifically between the exposed faces of the longitudinally inward plates 109. Thus, the length of a combined tread and riser unit to be cast is selectively predetermined. The screws 102 are then tightened to firmly fix the relative positions of the plate 109. The middle plate is then adjusted so that its extension is engaged between the inner and outer vertical plates 116 and 118, with the plates 116, 118 and disposed in their upstanding operative positions on the channel 94.

The clamp detent arms 108, being in rearwardly and upwardly swung positions, the panel 48 is put into place in the notches 80 in the heads 38, and the arms 108 then swung downwardly and forwardly so as to engage their detents 114 over the upper edge of the panel 43.

The machine 10 is now completely set for casting of a tread and riser unit of predetermined, specified dimensions. Concrete aggregate is poured into the space between the front panel 84 and the depending front flange 18 and the longitudinally inward vertical plates 116, and onto the base plate 14 between the plates 109 of the clamping brackets, and between the upstanding base plate rear flange 16 and that portion of the front panel 84 which extends above the base plate 14 to a height level with the upper edge of the rear flange 16. After the required setting time has elapsed, the top exposed surface of the concrete aggregate is troweled and edged. The front panel 84 is then removed after release of the detent 114 therefrom, whereupon the front exposed surface of the cast unit may be trowel finished. Upon proper curing, the completed unit is removed from the machine 10, and subsequently, either identical units, or units of other dimensions obtained by adjustment of the machine, can be similarly cast.

What is claimed is:

1. In apparatus for casting a concrete tread and riser unit, a horizontal longitudinal elongated base plate having rear and front longitudinal edges, a top surface, and opposite ends, an upstanding rear flange on and extending along said rear edge, a depending front flange on and extending along said front edge, said depending front flange having a lower edge, a pair of vertical end plates located beneath the base plate behind said front flange and secured to the base plate and the front flange in spaced relation to each other lengthwise of the base plate, bracket means mounted on said end plates having heads projecting forwardly beyond said front flange, journal means on said heads, a horizontal shaft extending between and having ends journaled in said journal means, vertical slideways on said heads, vertical rack bars slidably engaged in said slideways and having upper ends, a horizontal element extending between and secured at opposite ends to the upper ends of the rack bars, a removable vertical longitudinally elongated front panel having upper and lower edges, means on said heads supportably engaging the lower edge of the front panel and spacing the front panel forwardly from the base plate front flange, said horizontal element being positioned between and slidably engaged with the base plate front flange and said front panel, said rack bars having vertical racks thereon,

pinions, ahd means for rotating said "shaft in opposite directions to raise and lower said horizontal element relative to said base plate, vertical plates above said horizontal element and positioned between and slidably engaging said front flange and said front panel and having lower ends resting upon said horizontal element, said vertical plates being spaced from each other along said horizontal element, and longitudinal spaced second bracket means mounted on the rear base plate flange for longitudinal adjustment therealong and having guide extensions severally engaged with said vertical plates and positioning said vertical plates along said horizontal element in erect positions, said second bracket means including transverse vertical plates means resting on and rising from said base plate on which said guide extensions are mounted, said second bracket means further comprising pivoted arms having forward ends, and detents on said forward ends releasably engaged with the upper edge of the front panel.

2. In apparatus for casting a concrete tread and riser unit, a horizontal longitudinally elongated base plate having rear and front longitudinal edges, a top surface, and opposite ends, an upstanding rear flange on and extending along said rear edge, a depending front flange on and extending along said front edge, said depending front flange having a lower edge, a pair of vertical end plates located beneath the base plate behind said front flange and secured to the base plate and the front flange in spaced relation to each other lengthwise of the base plate, bracket means mounted on said end plates having heads projecting forwardly beyond said front flange, journal means on said heads, a horizontal shaft extending between and having ends journaled in said journal means, vertical slideways on said heads, vertical rack bars slidably engaged in said slideways and having upper ends, a horizontal element extending between and secured at opposite ends to the upper ends of the rack bars, a removable vertical longitudinally elongated front panel having upper and lower edges, means on said heads supportably engaging the lower edge of the front panel and spacing the front panel forwardly from the base plate front flange, said horizontal element being positioned between and slidably engaged with the base plate front flange and said front panel, said rack bars having vertical racks thereon, spaced pinions flXed on said shaft in mesh with said pinions, and means for rotating said shaft in opposite directions to raise and lower said horizontal element relative to said base plate, and releasable clamping block means mounted on the base plate front flange and engaged with said shaft for locking the shaft against rotation from a selected rotated position.

References Cited in the file of this patent UNITED STATES PATENTS Re. 12,542 Barker Oct. 23, 1906 1,347,356 Tonkin July 20, 1920 1,675,443 Bell July 3, 1928 2,416,559 Wilson Feb. 25, 1947 2,470,690 Dahle May 17, 1949 2,558,615 Johnson June 26, 1951 2,679,083 Eriksson May 25,1954 

